On Wed, Jun 02, 2010 at 07:35:09AM -0400, Olin Lathrop wrote:
> peter green wrote:
> > At least with microchip the friendlier end of SMT seems to be doing
> > even worse. Older 40/44 pin devices are availiable in DIP, PLCC and
> > TQFP but
> > for the newer 40/44 pin stuff the only choice is either DIP or TQFP
> > (which I certainly wouldn't reccomend to a beginner).
> 
> PLCC is long gone for good reason.  They are way too big, the leads too
> easily bent, and actually harder to solder than the TQFP because the leads
> bent under instead of coming out.  A Microchip 44 pin TQFP is really not
> that hard to solder, even with just a soldering iron.
> 
> If you guys could just get over the fear of something new, you'd see SMD
> parts are really not hard to use, and certainly not worth the phobia
> demonstrated here.

OK I'll bite. I ask with the caveat that I'm only coming from the hobby
perspective. SMD is obvious if you develop for a living. But for those of
us where everything is a one-off, custom, only for us design, I'm trying to
figure out exactly how it fits. So it comes down to a single question:

How do you prototype with SMD?

Through hole passes what I call the Radio Shack test: can I buy the parts I
need to do the job from Radio Shack at 3 PM on a Sunday afternoon? I'll
illustrate with an example. Last semester my Dean asked for a demo for
student orientation. I had been noodling with some persistence of vison
stuff and decided to wire a quick board with a PIC and some 3 color LEDs to
spin as an example. Had the PIC. Had the LEDs. Needed a board. Buy a
prototyping board that matches their solderless breadboard:

http://www.radioshack.com/product/index.jsp?productId=2102846

a couple of low profile IC sockets and some 150 ohm resistors. Use 22 gage
CAT5E twisted pair for jumper wire. Plug, solder, test, load, done.
Prototype from nothing in less than 1/2 day.

Now how does one do the same with SMD equipment? Something simple like a
PIC 16F88, MAX232, some caps, a resistor or two and an LED.

SMD had always been somewhat intriging to me because in theory one could
solder an entire board using a toaster oven or a hot plate. That alone
could be worth the hassle of designing then either making or waiting for a
PCB.

I'm just trying to figure out what exactly is the SMD equivalent of a
solderless breadboard, or a typical stripboard/protoboard for through hole
parts.

Something like this site looks like the ticket:

http://protoboards.theshoppe.com/proto_chip_pcb.html

Any other suggestions welcome.

> 
> 
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